Improved health economic assessments of sustainable transport solutions in urban environments

Abstract: Introduction: Part of the European Strategy to achieve climate neutrality in the transport sector is to increase the proportion of electric vehicles (EVs) and active commuting. Health co-benefits from reduced air pollution and increased active commuting are assumed to follow; however, all dimensions of expected health effects are not quantified nor valued monetarily. Current state-of-the art health impact assessments (HIAs) of air pollution assume immediate change in health with exposure; however, the time-window of importance for health outcomes is unknown. Moreover, the currently applied risk estimate of sick leaves in relation to air pollution is poorly generalizable due to outdated exposure assessment and subjective data on outcome. The overall aim of this thesis is to assess the health economic effects of sustainable urban transport solutions and improve the epidemiological knowledge base of air pollution effects. Methods: The health effects of increased active commuting and the resulting change in air pollution exposure were valued monetarily from a health care perspective, and a cost-effectiveness analysis of investment in bicycle infrastructure was conducted. A health economic assessment from a societal perspective was also conducted for an increased proportion of EVs in the vehicle fleet, considering a change in both exhaust and non-exhaust particles. The exposure-lag response between air pollution and risk for ischemic heart disease (IHD) and stroke was assessed in a multi-cohort study using distributed lag-nonlinear models (DLNMs). A case cross-over study design was applied to estimate the odds of sick leaves in relation to short-term PM2.5 exposure, and production losses were valued using the human capital method. Results: Investing in bicycle infrastructure to enable increased active commuting was estimated to be cost-effective from a health care perspective. An increased proportion of EVs was estimated to decrease population-weighted PM2.5 concentrations without the use of studded winter tires, but was estimated to increase with the current use of studded winter tires in Stockholm Sweden. For a 0-50% use of studded winter tires the health economic costs ranged between €20 and €122 million (M). An independent effect of PM2.5 on sick leaves was estimated to correspond to €2M per year in productivity loss for the population of Stockholm municipality. Exposure time windows closer in time and local sources of air pollution were suggested to be of greater importance for incident IHD and stroke.Conclusions: This thesis has demonstrated the health economic potential in policies seeking to transform the transport sector towards sustainability. Investment in the transport sector could lead to decreased morbidity and decreased monetary burden in the health care sector. Non-exhaust particles should be considered in order to fully assess the health economic effects of EVs. Moreover, the risk estimate of sick leaves in relation to air pollution exposure could be included in international HIAs.